What Causes Sharp Knee Pain?
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Sharp knee pain symptoms are often a sign of a serious knee injury. Learn about the causes of severe knee pain and treatment options for stabbing knee pain.
Sharp knee pain symptoms
The knee is the largest and most stressed joint in the human body. It is used in every movement — walking, jumping, running, even standing — and as a result, the knee is extremely vulnerable to injury. Most people, regardless of age, experience knee pain at some point in their lives. Older individuals may experience knee pain and discomfort due to multiple age-related conditions, and younger individuals may experience similar symptoms due to sports or other physical activities. However, sharp knee pain symptoms are often a sign of serious knee injury, and you should see a physician immediately.
Common accompanying symptoms of sharp knee pain
Symptoms often associated with sharp knee pain may include:
Sharp knee pain causes
Knee function and anatomy
The knee is a complex system of bones, cartilage, ligaments, tendons, and muscles responsible for weight-bearing and movement. See this image for a visual representation of these many components and how they connect. Any situation or condition that causes stress, inflammation or injury to any of these components can result in sharp knee pain.
- Bones: The bones of the knee include the femur (thigh bone), patella (kneecap), and tibia (shin bone). The knee joint works to keep these bones securely in place.
- Cartilage: The two types of cartilage in the knee are the minuscular cartilage and the articular cartilage. The cartilage act as cushions around the bones of the knee that reduce friction during movement, and help the bones move smoothly against each other. There is a medial meniscus on the inner side of the knee and a lateral meniscus on the outer side of the knee.
- Ligaments: The knee has four ligaments that connect bones to other bones and promote stability: medial collateral, lateral collateral, posterior cruciate, and anterior cruciate ligaments. These ligaments prevent the side-to-side movement of the femur as well as excessive backward and forward movement of the femur and tibia.
- Tendons: The tendons are similar to the ligaments and connect bone to muscle. The patellar tendon is the largest and attaches to the quadriceps.
- Joint capsule and bursa: The joint capsule and bursa are fluid-filled membranes that lubricate the joint and reduce friction.
Musculoskeletal causes of sharp knee pain may include the following.
- Ligament: Ligament injury in the form of sprains and tears is very common in sports, especially those that combine running with contact such as soccer, football, and rugby. Injury to the ligaments results in loss of stability and severe knee pain symptoms that often require surgery.
- Cartilage: Tears of the knee cartilage can occur when the knee twists while weight-bearing. These tears often occur during sports.
- Fracture: The various bones of the knee can be broken during car accidents and serious falls. In older people or individuals with weak bones, fractures can occur after trips or missteps.
- Mechanical: Problems with how the parts of the knee work together can result in sharp knee pain. Conditions such as Iliotibial band syndrome or dislocations of the kneecap often result in pain with movement.
Inflammatory causes of sharp knee pain may include the following.
- Arthritis: Arthritis is a general term for multiple conditions that cause painful inflammation and stiffness of the bones and joints. Arthritis can affect the bones and fluid-filled areas of the knee, resulting in significant irritation that can cause chronic and debilitating knee pain.
- Infection: The knee is susceptible to scrapes and cuts that easily allow bacteria to enter into the joint space. These infections can cause serious swelling, pain, and redness of the knee.
This list does not constitute medical advice and may not accurately represent what you have.
Infrapatellar bursitis is an inflammation of the bursa, or small cushioning sacs, beneath the patella, or kneecap. The condition may affect either the superficial bursa or the deep bursa.
Superficial infrapatellar bursitis is found in those whose work requires them to kneel on hard surfaces, and so it is known as housemaid's knee, clergyman's knee, parson's knee, or vicar's knee.
Deep infrapatellar bursitis can occur from chronic overuse, as with sports training and other hard physical work.
Either form of the condition can also be caused by hemorrhage, infection, traumatic injury, or inflammatory diseases such as arthropathy. Some cases may be idiopathic, meaning they occur in a particular individual for no clear reason.
Symptoms include swelling of the knee and pain below the kneecap.
Diagnosis is made through patient history and physical examination as well as x-ray, CT scan, or MRI.
Treatment involves rest; heat; nonsteroidal anti-inflammatory drugs to reduce pain and swelling; a knee brace; and sometimes corticosteroid injections into the knee.
Top Symptoms: pain in one knee, spontaneous knee pain, dull, achy knee pain, knee pain that gets worse when going up stairs, knee pain that gets worse when squatting
Patellofemoral pain syndrome
Patellofemoral pain syndrome (PFPS) is also called runner's knee, jumper's knee, anterior knee pain, chondromalacia patella, and patellofemoral joint syndrome.
Overuse through training for sports is a common cause, especially if there is a misalignment in the knee joint or a previous knee injury. This wears away the cartilage beneath the kneecap and causes pain on exercising.
It is most common in females and in young adults who are active in sports, but can affect anyone.
Symptoms include dull pain at the front of the knee and around the kneecap (patella) while running, squatting, or climbing stairs, or after prolonged sitting with knees bent.
Diagnosis is made through physical examination and through x-rays, CT scan, and/or MRI.
Treatment most often involves rest; over-the-counter pain relievers; low-impact exercise such as swimming or bicycling; physical therapy to strengthen and stabilize the knee; and orthotics (shoe inserts) to help correct a misaligned stride.
Surgery is needed only for severe cases, and is done through arthroscopy to remove any fragments of damaged cartilage.
Top Symptoms: knee pain, pain in one knee, knee pain that gets worse when going up stairs, dull, achy knee pain, knee pain that gets worse when squatting
Symptoms that always occur with patellofemoral pain syndrome: knee pain
Urgency: Primary care doctor
Knee bursitis (pes anserine bursitis)
Pes anserinus means "goose's foot. In this case it refers to the appearance of the three pes anserinus tendons which lie together at the inside of the knee, about two inches below the level of the kneecap.
Pes anserine bursae are small cushion-like structures which lie between the tibia, or shinbone, and the pes anserinus tendons. Inflammation of these bursae is called pes anserine bursitis.
Bursitis is most often caused by overuse. Pes anserine bursitis is found in runners, especially when training without sufficient warmup. It can also occur where there is osteoarthritis of the knee; a knee that turns outward; or obesity.
Symptoms include pain, tenderness, and swelling of the bursa, especially with climbing stairs or other exercise.
Diagnosis is made through physical examination and x-ray.
Treatment involves rest; ice; nonsteroidal anti-inflammatory drugs for pain and swelling; physical therapy; and sometimes corticosteroid injections into the injured bursa. Surgery may be done if conservative measures do not help.
Top Symptoms: pain in one knee, knee pain that gets worse when going up stairs, spontaneous knee pain, knee pain that gets worse when going down stairs, knee pain that gets worse when standing up
Symptoms that always occur with knee bursitis (pes anserine bursitis): pain in one knee
Arthritis is inflammation of one or more of the joints. Pain, swelling, and stiffness are the primary symptoms of arthritis. Any joint in the body may be affected by the disease, but it is particularly common in the knee.
Top Symptoms: pain in both knees, knee stiffness, knee instability, swollen knee, morning joint stiffness
Symptoms that always occur with knee arthritis: pain in both knees
Urgency: Primary care doctor
Jumper's knee (patellar tendonitis)
Jumper's knee is also called patellar tendinitis or patellar tendinopathy. It is an inflammation of the patellar tendon, which runs from the bottom of the patella – or kneecap – to the top of the shinbone.
It is most often an overuse injury seen in athletes, especially those in sports involving jumping, but it can affect anyone. Strenuous physical activity without warming up first, or tightness and inflexibility in the muscles of the thighs, can put additional strain on the patellar tendon.
Symptoms include pain just below the kneecap. At first it may only appear during exercise, but later becomes chronic as the tendon becomes more damaged and inflamed. Eventually the pain interferes with normal movement.
It is important to get treatment, as the condition will not heal on its own and will only get worse through forced movement.
Diagnosis is made through patient history, physical examination, and imaging such as ultrasound or x-ray.
Treatment involves rest; pain relievers; physical therapy to return flexibility to the tendon; and sometimes corticosteroid injections or surgery.
Top Symptoms: pain in one knee, spontaneous knee pain, knee pain that gets worse when going up stairs, knee stiffness, knee pain that gets worse when squatting
Urgency: Primary care doctor
The menisci are the two pieces of cartilage serving as shock absorbers in the knee, between the lower end of the thighbone and the top of the shinbone. A torn meniscus is commonly referred to as "torn cartilage" in the knee.
Damage to a meniscus often happens along with another injury to the knee, especially when there is any forceful, twisting movement or a direct hit such as a tackle.
Older people may tear a meniscus through normal activity if the cartilage has become thin and worn due to aging.
Symptoms include pain, stiffness, and swelling. The knee will simply not work correctly and may catch, lock up, or give way.
Diagnosis is made through patient history, physical examination, simple motion tests, and imaging such as x-ray or MRI.
Depending on the exact form of the injury, the tear may be allowed to heal on its own with supportive care such as rest, ice, and nonsteroidal anti-inflammatory pain medication. In other cases, arthroscopic surgery followed by rehabilitation may be needed.
Top Symptoms: pain in one knee, knee stiffness, knee instability, pain in the inside of the knee, swollen knee
Urgency: Primary care doctor
Iliotibial (it) band syndrome ('runner's knee')
Iliotibial band syndrome is also called ITBS or IT syndrome. The iliotibial band is a long, thick piece of connective tissue that begins at the top of the hip bone, runs down the outside of the leg, and attaches at the side of the knee.
ITBS is an overuse syndrome. Athletes in heavy training are susceptible to it, especially runners and cyclists. Pain and inflammation result if the far end of the iliotibial band constantly rubs against the outside of the knee joint.
Symptoms include pain on the outside of the knee, especially while running or while sitting with the knee flexed.
Diagnosis is made through patient history and physical examination, with simple stretching tests to identify the exact location of the pain. An MRI is sometimes ordered.
Treatment involves rest; ice; over-the-counter nonsteroidal anti-inflammatory drugs; stretching exercises for the iliotibial band; strengthening of the upper leg muscles; and, if needed, changes in the way the person strides or trains. Corticosteroid injections can be helpful and surgery may be tried in some cases.
Top Symptoms: knee pain, pain in one knee, dull, achy knee pain, knee pain that gets worse when going down stairs, sharp knee pain
Symptoms that always occur with iliotibial (it) band syndrome ('runner's knee'): knee pain
Urgency: Primary care doctor
Prepatellar bursitis is an inflammation of a fluid-filled sac (bursa) located in front of the knee (prepatellar) that normally acts as a cushion to help reduce friction. It can be caused by prolonged kneeling, such as for work, or due to injury or infection, and can either be ..
Fibromyalgia is a set of chronic symptoms that include ongoing fatigue, diffuse tenderness to touch, musculoskeletal pain, and usually some degree of depression.
The cause is not known. When fibromyalgia appears, it is usually after a stressful physical or emotional event such as an automobile accident or a divorce. It may include a genetic component where the person experiences normal sensation as pain.
Almost 90% of fibromyalgia sufferers are women. Anyone with rheumatic disease, such as rheumatoid arthritis or lupus, may be more prone to fibromyalgia.
Poor sleep is often a symptom, along with foggy thinking, headaches, painful menstrual periods, and increased sensitivity to heat, cold, bright lights, and loud noises.
There is no standard test for fibromyalgia. The diagnosis is usually made when the above symptoms go on for three months or more with no apparent cause.
Fibromyalgia does not go away on its own but does not get worse, either.
Top Symptoms: fatigue, arthralgias or myalgias, anxiety, depressed mood, headache
Symptoms that always occur with fibromyalgia: arthralgias or myalgias
Urgency: Primary care doctor
A dislocated kneecap is when the bone that covers the knee joint, the kneecap or patella, is moved out of place. The kneecap is normally held in place by tendons that connect it to muscles around the knee joint. Dislocation can be caused by planting the foot and twisting a flexed kn...
Sharp knee pain treatments and relief
When to see a doctor
Severe knee pain requires professional medical attention. Treatment depends on the specific diagnosis and may include one or all of the following:
- Physical therapy: After many knee injuries, your doctor will suggest physical therapy to restore range of motion, strength, and stability to your knee.
- Medication: If your severe knee pain is due to inflammatory conditions, your doctor may prescribe antibiotics to treat an infection or anti-inflammatory medications to treat arthritic conditions.
- Surgery: Fractures and tears of the ligaments and cartilage of the knee often require surgical intervention but often have great success.
There are many measures you can take in your daily life to prevent knee injury and severe pain, such as the following.
- Maintain a healthy weight: The knees bear all of the body's weight, so extra pounds can cause unnecessary stress and strain, increasing risk of injury.
- Be strong and flexible: The quadriceps and hamstring muscles provide support to the knee joint, so keeping them strong, conditioned, and flexible will benefit the functioning of the knee as a whole.
- Practice technique: If you participate in competitive sports and practice often, ensure that your techniques and movements are not putting unnecessary stress on your knees. Work with a coach to ensure that when you run, jump or move side-to-side, your knee is in the best position to prevent injury.
- Listen to your body: If you find yourself experiencing mild or transient knee pain after certain activities, listen to your body and take a break! Rest, ice and elevate your knee once you first notice sharp knee pain symptoms and make an appointment with your doctor promptly.
Questions your doctor may ask about sharp knee pain
- Is the knee pain affecting one or both knees?
- Where is your knee pain?
- How would you explain the cause of your knee pain?
- Do you often feel your knees buckling?
Self-diagnose with our free Buoy Assistant if you answer yes on any of these questions.
Dr. Gambrah-Lyles is a resident pediatrician at the Children's Hospital of Philadelphia. She is a graduate of the University of Pennsylvania Perelman School of Medicine (2019). She graduated cum laude and received her undergraduate degree in Biochemistry and Spanish from Washington University in St. Louis (2013). Her research explores the intersections between neurology, public health, and infectious disease. She has investigated nutrition and cerebral palsy in Botswana, and completed a year-long project in Brazil, researching growth and developmental outcomes of Zika virus infection in pediatric patients as a Doris Duke International Scholar. Dr. Gambrah-Lyles speaks four languages, loves staying active, and enjoys sharing her love for medicine through teaching and writing.
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